21573887 has 2 divisors, whose sum is σ = 21573888. Its totient is φ = 21573886.

The previous prime is 21573863. The next prime is 21573907. The reversal of 21573887 is 78837512.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21573887 - 2²⁰ = 20525311 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21573857) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10786943 + 10786944.

It is an arithmetic number, because the mean of its divisors is an integer number (10786944).

Almost surely, 2^21573887 is an apocalyptic number.

21573887 is a deficient number, since it is larger than the sum of its proper divisors (1).

21573887 is an equidigital number, since it uses as much as digits as its factorization.

21573887 is an evil number, because the sum of its binary digits is even.

The product of its digits is 94080, while the sum is 41.

The square root of 21573887 is about 4644.7698543631. The cubic root of 21573887 is about 278.3830571599.

The spelling of 21573887 in words is "twenty-one million, five hundred seventy-three thousand, eight hundred eighty-seven".